From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A85F8CC6B34 for ; Thu, 15 Oct 2026 12:55:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:MIME-Version: Content-Transfer-Encoding:Content-Type:References:In-Reply-To:Date:Cc:To:From :Subject:Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=zL4P1buyUO0HTa8tz5fIfgHMxvjhBM1cuXeP1N+bW10=; b=3pPg6Fx/3KVLE2x1rWzBllQzos huB9bcGSJhc2H0QHX0Kmt3OEVRmVWL/863CplXyqfEUfIOgWKNta7toyxS+VeUHynSIv/8bx1PbTX rER+srmyXg3QZ94122uKGDyGY2DUPq+8KWA0+CCutghrNXDBbz8HIIQ2hApUz2X9T3lje6ySdR/jT BWIOXfbJIuVgSrrXnDVlom/m2aIVwgOqR0A25oeLaF8uV03K+R5U4HCloE5XFanduu8HcpRvELtBp H8AnWqtit8R9asSTMK8dnhXKR8BMS6FsI9alH1mfu0iaC6CclWQFJ8rwDS/1jsyTcVV5yYoHiY2hy CF4/E/5w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xHKzo-00000000B5v-1OTY; Thu, 15 Oct 2026 12:55:44 +0000 Received: from s3.sipsolutions.net ([2a01:4f8:242:246e::2] helo=sipsolutions.net) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1xHKzi-00000000B1u-2EIX for linux-um@lists.infradead.org; Thu, 15 Oct 2026 12:55:42 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sipsolutions.net; s=mail; h=MIME-Version:Content-Transfer-Encoding: Content-Type:References:In-Reply-To:Date:Cc:To:From:Subject:Message-ID:Sender :Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-To: Resent-Cc:Resent-Message-ID; bh=zL4P1buyUO0HTa8tz5fIfgHMxvjhBM1cuXeP1N+bW10=; t=1792068938; x=1793278538; b=MSxZMje/+/N806TMUUEsQ5myBXcDW2WUnP5w47srPrCICJ5 mMTLqWgvhnk/FtladFoMBFSxysoe+XA+yvjRgJ+rVvDlITh9Pnaio2fGAvjU8nPAvfZpXSSZ7L2KX /X3VS71p1X33tUpUNNNU+jxnGV2YERTWRJWrUKz8QaXvJhHWM/5muIzIrSMRyZArnsH7S0mUq+JWN tCBzFBGIP1e/77YVt3m82mGdqwanqLaGW2mO7mJEME/4DhnxSTWclwfd6GFp24GaII2rSldv0L/To bVva6yRsnpzPEH4q9ot0agNHax6HBnMZ0LMae0M1Wv2oEUcf/ryhUtj+XtJZyNZg==; Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_X25519__ECDSA_SECP256R1_SHA256__AES_256_GCM:256) (Exim 4.98.2) (envelope-from ) id 1xHKzU-00000003bXE-0Kyl; Thu, 15 Oct 2026 14:55:24 +0200 Message-ID: <64ee40b97fc447bbf3abb80250ad0d9f3cf3c6fa.camel@sipsolutions.net> Subject: Re: [PATCH net-next v2 2/7] um: vector: honor virtio net hdr conversion failures From: Johannes Berg To: "Michael S. Tsirkin" Cc: linux-kernel@vger.kernel.org, Willem de Bruijn , Jason Wang , Eugenio =?ISO-8859-1?Q?P=E9rez?= , Xuan Zhuo , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , netdev@vger.kernel.org, virtualization@lists.linux.dev, Rusty Russell , Max Krasnyansky , Richard Weinberger , Anton Ivanov , linux-um@lists.infradead.org Date: Thu, 15 Oct 2026 14:55:23 +0200 In-Reply-To: <20261015085119-mutt-send-email-mst@kernel.org> References: <6716834884238de0ab1ab313004044122aa2adbf.1792067836.git.mst@redhat.com> <8420ba1fe84fc7d105825026802d4ad10d44af71.camel@sipsolutions.net> <20261015085119-mutt-send-email-mst@kernel.org> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.60.2 (3.60.2-2.fc44) MIME-Version: 1.0 X-malware-bazaar: not-scanned X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261015_055538_625409_EC9CF70C X-CRM114-Status: GOOD ( 21.74 ) X-BeenThere: linux-um@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-um" Errors-To: linux-um-bounces+linux-um=archiver.kernel.org@lists.infradead.org On Thu, 2026-10-15 at 08:52 -0400, Michael S. Tsirkin wrote: > On Thu, Oct 15, 2026 at 02:47:01PM +0200, Johannes Berg wrote: > > On Thu, 2026-10-15 at 08:41 -0400, Michael S. Tsirkin wrote: > > > virtio_net_hdr_to_skb() refuses packets whose checksum metadata > > > it cannot make sense of, but the vector raw transport ignored > > > its return value: rejected packets went on into the stack with > > > their metadata unvalidated. > > >=20 > > > Propagate the failure. > > >=20 > > > Assisted-by: LLM > > > Signed-off-by: Michael S. Tsirkin > > > --- > > > arch/um/drivers/vector_transports.c | 4 +++- > > > 1 file changed, 3 insertions(+), 1 deletion(-) > > >=20 > > > diff --git a/arch/um/drivers/vector_transports.c b/arch/um/drivers/ve= ctor_transports.c > > > index e1fb2a76fdff..8b7548458663 100644 > > > --- a/arch/um/drivers/vector_transports.c > > > +++ b/arch/um/drivers/vector_transports.c > > > @@ -210,7 +210,9 @@ static int raw_verify_header( > > > return 1; > > > =20 > > > skb_set_network_header(skb, ETH_HLEN); > > > - virtio_net_hdr_to_skb(skb, vheader, virtio_legacy_is_little_endian(= )); > > > + if (virtio_net_hdr_to_skb(skb, vheader, > > > + virtio_legacy_is_little_endian()) < 0) > > > + return -1; > > > return 0; > > >=20 > >=20 > > Seems it'd be simpler to just > >=20 > > return virtio_net_hdr_to_skb(...); > >=20 > > As far as I can tell, the function only returns -EINVAL or 0 (never a > > positive value), and the caller only cares about negative (error) or > > positive (no checksum needed), so that'd be equivalent? > >=20 > > johannes >=20 > if raw_verify_header can safely return any errno - i did not want to > audit it. You already used an LLM and still didn't want to? ;-) I checked briefly (by hand) and it seems fine, it's assigned to the function pointer, which only has two callers on the _kern.c side. johannes